The different lights on a car serve specific functions for visibility and communication. They are generally categorized into exterior lights and interior lights. Exterior lights include headlights (low and high beams), daytime running lights (DRLs), turn signals, taillights, brake lights, fog lights, and hazard lights. Interior lights consist of dome lights, map lights, and dashboard illumination. Using them correctly is crucial for safe driving.
Headlights are your primary source of illumination for driving at night or in poor weather. Low beams provide a short-range, wide pattern to light the road without blinding oncoming traffic. High beams offer intense, long-distance light for dark, unlit roads but must be dimmed for other vehicles. Many modern cars use LED or HID systems for greater brightness and efficiency compared to older halogen bulbs.
Daytime Running Lights (DRLs) are automatically activated low-intensity front lights that make your vehicle more visible during daylight hours. Turn signals, also known as blinkers, are amber lights that flash to indicate your intention to turn or change lanes. Your taillights are red lights that turn on with your headlights, making you visible from behind. Brake lights are brighter red lights within the same housing that illuminate when you press the brake pedal.
Fog lights are mounted low on the front bumper to cut through fog, rain, or snow with a wide, bar-shaped beam that minimizes glare back at the driver. Rear fog lights, sometimes brighter than standard taillights, are also found on some models. Hazard lights simultaneously flash all turn signals to warn other drivers of a stationary vehicle or a traffic hazard.
| Light Type | Common Color | Primary Function | Key Regulation / Standard |
|---|
| Low Beam Headlight | White/Yellow | Nighttime driving, oncoming traffic | SAE J1383 / FMVSS 108 |
| High Beam Headlight | White | Maximum dark road illumination | SAE J1383 / FMVSS 108 |
| Daytime Running Light (DRL) | White/Amber | Daytime visibility | FMVSS 108 |
| Turn Signal | Amber | Indicate direction change | SAE J588 / FMVSS 108 |
| Taillight | Red | Visibility from behind at night | SAE J585 / FMVSS 108 |
| Brake Light | Red | Signal braking | SAE J586 / FMVSS 108 |
| Fog Light | White/Yellow | Visibility in poor weather | SAE J583 |
| Hazard Light | Amber (all corners) | Warn of vehicle hazard | FMVSS 108 |
Inside the car, the dome light illuminates the entire cabin, typically activated when a door is opened. Map lights are smaller, focused lights for the driver or passenger to see specific items without distracting the driver. The dashboard contains various warning lights (like the check engine light) and gauge illumination, which are critical for monitoring the vehicle's status.
